Manufacture of Sound Absorbing Material from Recycled Rice Straws for Room Acoustics Improvements

Abstract

The Philippines, as an agricultural country, produces an excessive amount of rice straws. Burning of these huge amounts of rice straw is also discouraged due to the harmful effects in the environment such as air pollutions and the like.  A good way of disposing the huge amount of rice straw is to recycle and use them as components of sound absorbing composite wood boards that may be used to improve the acoustic quality of the room. The composite wood board, with a size of 2’ by 3’ with a thickness of 1”, is produced with the use of wood chips and rice straw with urea formaldehyde resin as the binder using the same wood-based board manufacturing methods. The sound absorption coefficient was determined by using Sabine’s Equation by recording the reverberation time at various sound levels with use of a sound level meter. Through measurements, it is estimated that the absorption coefficient of the composite wood board ranges from 0.011 to 0.188 which is somewhat similar to that of the absorption coefficient of masonry walls